In a known semiconductor device production method, a plurality of wafers with semiconductor devices or semiconductor integrated circuits formed thereon in advance are laminated together, and the laminated wafers are electrically connected by vertical wirings to form 3-dimensional laminated semiconductor circuit devices. With this way of producing 3-dimensional laminated semiconductor circuit devices, an upper layer wafer and a lower layer wafer with semiconductor devices or semiconductor integrated circuits formed thereon in advance are laminated, and an insulating resin is injected between the upper and lower layer wafer to produce 3-dimensional laminated semiconductor circuit devices.
For example, Patent Literature 1 discloses a method for producing semiconductor devices wherein a plurality of semiconductor chips that have been diced into chips are laminated within an enclosure. A resin is then introduced into the enclosure through a plurality of slits to form an insulating resin layer between the semiconductor chips.
Patent Literature 2 discloses a method related to the manufacture of laminated wafers wherein rectangular copper walls are formed on a wafer surface to serve as a seal when the wafers are joined together, and a vacuum differential pressure is used to inject resin.
FIG. 17 shows the steps involved in using a seal to inject an insulating adhesive into the inter-wafer space. With this injection process that uses an adhesive injection device 200, a copper wall 203 is formed to enclose copper bumps 201 that are formed on a wafer with an inlet opening 204 formed at a portion of the copper wall 203 (FIG. 17(a)). After a vacuum is created, the inlet opening 204 is immersed into an insulating adhesive 205 (FIG. 17(b)), N2 gas is then introduced into the adhesive injection device to break the vacuum and create an atmospheric pressure (FIG. 17(c)), causing the insulating adhesive 215 to be injected into the inter-wafer spaces (FIG. 17(d)).
Patent Literature 2 discloses another method for injecting resin between laminated wafers but does not involve forming a seal on the laminated wafers. With this method, an adhesive is disposed around the entire periphery of a wafer, and the resin is injected using vacuum differential pressure.
In FIG. 18, vacuum chamber 215 of the adhesive injection device 210 includes vessel 211 made of an upper jig 212 and a lower jig 213, and an upper stage 213 and a lower stage 214 which fix the vessel 211. Laminated wafers 220 are placed inside the vessel 211. The vacuum chamber 215 is connected to a vacuum evacuation apparatus 216 which creates a vacuum inside the vacuum chamber, an inert gas introduction unit 217 which introduces an inert gas into the vacuum chamber and an adhesive supply unit 218 which supplies adhesive into the vessel 211.
By introducing an inert gas into the vessel 211, a pressure difference is created between the vessel and the laminated wafers. The pressure difference is used to inject an adhesive from the entire periphery of the laminated wafers.